Cylinder liners for car and truck engines are normally centrifugally cast. The reason for this is that the phosphorous-alloyed grey iron which is normally employed is almost impossible to cast in a conventional green sand mold because the iron is particularly susceptible to shrinkage. In centrifugal casting, a heated mold is employed which is made up of rotating tube, the mold cavity of which having a thin layer of an insulating material. Due to the effect of the centrifugal forces, the shrinkage of the cast product is compensated for.
Centrifugal casting does however impart limitations as to the strength of the material due to the fact that the quick cooling during solidification i.a. precludes high alloying with carbon-stabilizing alloying elements and low C.sub.eq, these being the most common measures which can be employed to increase strength. Other disadvantages are that the centrifugal casting breaks up the first precipitated reinforcing primary austenitic dendrites in the structure and centrifugally separates primary austenite and graphite eutecticum at low C.sub.eq.
In order to avoid these problems, cylinder liners could, for example, be cast in stable molds of cold hardening mold material or core sand, though such molds are very expensive and detrimental to the environment.